



Patented Sept, 8, 1936 U l'l'E l) ST 3.,1

PROCESS FOR RETARDING THE ABSORP- TION F DYESTUFFS BY THE FIBER No Drawing. Application September 10, 1934, Serial No. 743,484. 1111 Switzerland September 6 Claims.

According to this invention the absorption of dyestufis by fibrous material is retarded by means of a dispersing agent containing, on the one hand, at least one basic nitrogen atom and at least one sulfo-group, which may be linked to a carbon atom or otherwise, e. g. to an oxygen atom, and, on the other hand, an aliphatic or cycloaliphatic radical containing at least 8 carbon atoms. By the expression aliphatic or cycloallphatic radical containing at least 8 carbon atoms there are to be understoodnot only chains merely consisting of carbon atoms, but also chains which are interrupted by an oxygen-, sulfuror nitrogen-bridge.

Examples of such dispersing agents are the sulfonic acids of cyclic amidines, such as are described in applications Serial No. 667,133 and No. 743,483, or obtained by sulfonation of the amidines described in the application Serial No. 727,584, as well as mixtures of such sulfonic acids.

If a water-soluble compound of this kind is added to a dye-bath the absorption of the dyestuii is verysubstantiallyretarded,so that in many cases there is a substantial improvement in the levelness of dyeings produced with the aid of such dyestuffs which would otherwise be rapidly absorbed. This eiiect can already occur in dyeing with basic dyestuffs cotton which has been mordanted with tannin or in some other suitable manner. The improvement in the levelling capacity may further be observed in the case of such direct-dyeing dyestuffs which are used for dyeing cellulosic fibers, such as cotton, artificial silk from regenerated cellulose, hemp, and ramie. It is also clearly observed in the case of dyestufis intended for'dyeing animal fibers, such as wool or silk, particularly also in the case of acid dyestuffs which are rapidly absorbed, such as dyestufis fast to milling, which must be dyed in an 40 acetic acid bath. However, this effect is of particularly great practical importance in the case of alkaline baths containing hydrosulfite or other reducing agents having a similar action, and dyestuffs capable of being dyed in the reduced state, 45 such as sulfuror vat-dyestuffs, particularly vatdyestuffs of the anthraquinone series being rapidly absorbed by the fibers. the absorption capacity results, on the one hand, in an improvement of the levelness of the dyeings obtained, and, on the other hand, in an increase in the capacity for alkaline reducing baths to strip dyeings produced with vat-dyestufis. Thus Whilst many vat-dyestuff dyeings are scarcely affected by alkaline reducing baths, the addition to the bath of a compound used in accordance with the invention has the result that the dyeings undergo a pronounced weakening which renders it possible to improve the levelness oi. unlevel defective vat-dyeings. When used in dye-baths containing reducing agents those The retardation of among the above cited products have proved particularly eifective which contain such sulionated benzimidazole derivatives which are substituted at the ,u-CZLIbOIl atom or at the N-atom by a longer aliphatic chain which may be interrupted. Among these, as is the case quite generally, the monosulfonic acids are particularly .valuable. Further such sulfonic acids in which imidazoles, represent valuable new agents which are used both for dyeing vat dyestufis and for stripping textile materials dyed with vat-dyestuffs.

The following examples illustrate the invention:-

Example 1 There is added to the dye-bath, containing 0.5 per cent. of trichloroisodibenzanthrone, vatted in the usual manner in an alkaline hydrosulfite bath, the sulfonated cyclic amidine, obtained by sulfonation of N-methyl-,uheptadecylbenzimidazole, in quantity amounting to 0.25 gram per liter of dye-bath. The absorption of the dyestuff from the bath is appreciably retarded, so that the dyeings obtained are more level and the material is better through-dyed than is the case in the absence of the sulfonated amidine. The N-alkyl, N-propyl or N -buty1- .-heptadecylbenzimidazolesulfonic acids behave quite similarly.

Example 2 A material which has been dyed with 1.5 per cent. of Cibanone Blu'e 3G (Schultz, Farbstoi ftabellen No. 1,279) but which is defective owing to unlevelness, is treated for half-an-hour at 60 C. in a bath-containing per liter, 16 cc. of an aqueous solution of sodium hydroxide of B. and 2 grams of sodium hydrosulfite. By the addition of 1 gram per liter of the sulfonated cyclic 'amidine, prepared by sulfonation of the mixture of N-methylated imidazoles from ortho-phenylenediamine and hydrogenated fish oil, the reabsorption of the reduced dyestuff which has been removed .is retarded, whereby the dyeing is levelled. The product may also be used for stripping vat-dyeings.

'- Example 3 "A shirting material which has been dyed with 0.5 per cent. of Cibanone Blue (3CD (Schultz, Farbstofitabeilen, 7th edition, 1931, No. 1,234) and is unsuitable for making up into clothing owing to unievcl dyeing, is treated in a jigger for half-an-hour at 60" C. with a solution containing per liter 15 cc. of an aqueous solution of sodium hydroxide of 36" B., 5 grams of sodium hydrosuifite and 0.2 gram of the product prepared by suifonating a mixture of 25 per cent. of N-methyl- -heptadecylbe'nzimidazole and per cent. of NzN- methyl-ethyl- .-heptadecylbenzimldazoiium chloride.

There is obtained in this manner a piece material which is dyed uniformly throughout and is suitable for making up into clothing. Similar resuits are obtained when using other quantitative proportions than indicated in the first paragraph of this example, e. g. 30 to 70, 50 to 50 or 70 to 30.

Example 4 A padding bath is prepared with 50 grams of Cibanone Violet 2R double paste (Schultz, Farbstoiltabellen, 7th edition, 1931, No. 1,265) and 5 grams of the product of the suli'onatlon of a mixture of 25 per cent. oi N-methyl- -heptadecylbenzimidazole and '75 per cent. of N.N-methylethyl- L-heptadecylbenzimidazolium chloride.

A linen fabric is passed repeatedly through the bath and intermedlateiy between squeezing rollers. The dyeing is then developed in a Jigger by treating the fabric at 60 C. with a liquor containing per liter 16 cc. of sodium hydroxide solution of 36 B. and 2 grams of sodium hydrosulfite.

The fabric is thus dyed very levelly and is well through-dyed. Similar results are obtained when using other quantitative proportions than indicated in the first paragraph of this example, e. g. 30 to 70, 50 to 50 or 70 to 30.

Example 5 For dyeing kilos of loose wool, a dye-bath of about 1000 liters and having a temperature of 55 C. is prepared with the aid of 500 grams of glue, 500 cc. of ammonia of specific gravity 0.9, 300 grams of sodium hydrosulfite and 500 grams of the sodium salt of suii'onated N-methyl- -heptadecylbenzimldazole. Thereupon'there are added 2.5 kilos of Ciba Blue' 2B (Schultz, Farbstofltahellen, 7th edition, No. 1,314) which have previously been vatted in the customary manner. 1

The addition of the suii'onated benzimidazole derivative has the effect of retarding appreciably absorption of the dyestufi so that the whole batch is dyed much more levelly than in the absence of such a derivative. The bcnzimidazole-sullonic acids alkyiated at the N-atom mentioned at the end of Example 1 behave similarly.

Example 6 For dyeing mercerized bead yarn there is added to the dye-bath. containing 0.5 per cent. of Cibanone Violet 2R (Schultz, Farbstofltabellen, 7th edition, No. 1,265) or 0.5 per cent. 01 Cibanone Blue 3G (Schultz, Farbstoiltabellen, 7th

edition, No. 1,279) vatted in the customary man- Example 7 Cotton piece goods are dyed in a jigger with an alkaline hydrosulfite bath containing 0.5 per cent. of Cibanone Violet 2R (Schultz, Farbstofitabelien, 7th edition, 1931, No. 1,265), with the addition, per liter of dye-bath, of 0.5 gram of the sodium salt of the-product prepared by suitonating the quaternary hexadecyl-phenyl-dimethyl-ammonium-methylsuliate. The dyeings are appreciably more level than those obtained without this addition.

A like effect is obtained it instead of the aforesaid addition there is added, per liter of dyebath, 1 gram of the sodium salt of sulfonated methyl-hexadecyl-aniiine, or 2 grams of the sodium salt of sulfonated hexadecyl-aniiine.

Example 8 Cotton drapery material is dyed by means of 20 per cent. of Pyrogene Indigo (Schultz, Farbstofitabellen, 'lth edition, No. 1,110) in a bath containing besides the usual additions, 0.3 gram per liter of the sodium salt of N-methyl-heptadecylbenzimidazol-sulfonic acid.

Owing to the addition or this substance the dyestuil is appreciably more slowly absorbed; the dyeing is much more level and the material is better through-dyed. Furthermore, the dyeing shows no tendency towards bronzing.

What we claim is:-

1. Baths used for treating textile materials containing cellulose, which baths are characterized by a content of alkali, a reducing agent, and a sulfonated benzimidazole substituted at the -carbon atom by an aliphatic chain having at least 8 carbon atoms.

2. Baths used for treating textile materials containing cellulose, which baths are characterized by a content oi alkali, hydrosulfite, and a sulfonated benzimidazole substituted at the u-carbon atom by an aliphatic chain having at least 8 carbon atoms.

3. Baths used for treating textile materials containing cellulose, which baths are characterized by a content of alkali, hydrosulfite, and a sullonated benzimidazole substituted at the -carbon atom by the heptadecyl radical.

4. Baths used for treating textile materials containing cellulose, which baths are characterized by a content of alkali, hydrosulflte, and a suli'onated benzimidazole substituted at the -carbon atom by the heptadecyl radical and at at least one nitrogen atom by an alkyl radical containing not-more than 4 carbon atoms.

5. Baths used for treating textile materials containing cellulose, which baths are character ized by a content of alkali, hydrosulfite and an alkali salt of the sultonated Nmethyl- -heptadecylbenzimidazole.

6. Baths used for treating textile materials containing cellulose, which baths are characterized by a content 01 alkali, hydrosulfite and an alkali salt oi a sultonated mixture 01 N-methyl- -heptadecylbenzimidazole and N-methyl-N'- ethyl- -heptadecylbenzimidazoiium chloride.

CHARLES GRAENACHER. FRANZ ACKERMANN. ALBERT LANDOLT. WILHELM GEIGY. 

